Study of medieval enamelling on gilded objects combining SEM-EDAX and PIXE

A set of fragments of metallic artefacts from the medieval period excavated from Ciudad Real in Spain has been studied. The objects are gilded copper buckles with a champlevé enamelling decoration. The composition of predominantly blue-coloured enamels has been analysed using three non-destructive techniques, SEM-EDAX (scanning electron microscopy coupled with energy-dispersive X-ray analysis), X-ray fluorescence (XRF) and PIXE (particle-induced X-ray emission). Analyses show that Co is responsible for the blue colour. The results of the two techniques are compared, as well as the main components which constitute the enamel. Analyses suggest that Cu is responsible for red colour.